There is this change in the latest SU3 BETA:
I loaded up to try KSAV airport and there is thunder and lightning in live weather! First time I’ve seen it in years
I have lightning, and thunder at LOWS right now. Infrequent but it’s there.
After YEARS, I was stunned to see again lightnings in FS2020! Yesterday I was having a testflight around my hometown: storm in real life and a storm with lightnings and thunders in fs2020 as well! What a gift, haha!
Ha ha… same here. It has been years. And I was stunned too. 
a few weeks ago some appeared in various dark cloud formations i was flying around. Not bolts just various flashes within the cloud
flew today around Lyon and LFLC and from small clouds around 4000ft high and 18000 ft wide I have seen quite a lot of lighting happening cloud - ground lighting
Lightning and thunder are there. What I am hoping to see soon is more detailed and pronounced cumulonimbus clouds and cells in the distance. That’s still missing.
Not being able to fly along a line of storms and see thunderheads and the wall of clouds flickering with lightning is pretty wild. I know there are a lot of people in this thread upset about it, but I am surprised that the lack of proper depiction of hazardous weather is not actually a much bigger controversy among the community.
I agree. I think with the flawed launch, need to improve performance it became a back burner item. It is however still clearly a problem in both 2020 and 2024.
Just been flying MF2020 under real weather in my zone, with intense lightning and thunder in real life but none in the game.
So should we use active sky instead?
That is a question you need to decide for yourself.
If you aren’t happy with the default weather, and after reading through articles here if it seems like it could help, you may want to get it.
I’ve not tried flying in my local area during a thunderstorm to compare with the actual weather at the time, but I’ve definitely experienced plenty of lightning and thunder in other locations. Without actually being there, I can’t say how closely it mirrored the real conditions, but it’s definitely in the sim.
If only I was home right now, I’d test it.
A handy site for hunting adverse weather conditions is this:
The most intense I’ve ever observed in-game. 
I have thunder, and lightning here:
https://badbadweather.com/rain
METAR SAZM 062000Z 10018G31KT 5000 -TSRA FEW015 OVC035 FEW045CB 15/15 Q1005 RMK PP///